JD 425 Leaky rear-end (not mine, the tractor's)

[SATOHBULL]

Those lines are only under pressure when the engine is running. The leak may well be around the differential lock shaft, common location if it's on the left.

I'd suggest pulling the seat pan first. Makes it a lot easier to clean a look it over. Just a few bolts, 2 each side holding it to the foot rest, and two holding it down under the seat edges near the rear.

That will let you see another fairly common leak area, the forward and reverse check valves. They sometimes leak around the little pin that gets pusshed down to allow it to freewheel. The leak will come down the front of the case, similar to your description.

 

[MikeC1974]

Bull -
Could I ask a couple of rather simple questions:
1) What does the forward/reverse check valve look like?
2) What does the differential lock shaft look like?

Are both of those on the left side?
When looking down onto the differential, after I blew everything out, I see a pin - looks to be about 1/2" in diameter, that looks like it slides in and out. I believe that's the differential lock shaft.

One last simple question - will just starting it and letting it run, force the leak, in your opinion? Kinda hard to ride it with the pan off and gas tank freewheeling.

Thanks Bull, and everyone, for your assistance.

 

[bb218hlv]

The differential lock is as you described, not sure there is a check valve for forward / reverse, should just be a rod attached to a shaft that will pivot as you move the shifter. Again I would look really close at the alum case, the cracks on mind were so fine that by luck I seen the oil weep a drip from there. Mine would leak on my floor where I parked it the next week when I was ready to mow again it would see the oil on the floor, it was not a pressure leak.

 

[SATOHBULL]

the check valves are located under the seat pan on top of the transaxle. With it off you can clearly see the valves. They are operated by the free wheel lever on the right.

 

[MikeC1974]

So I ended up taking it to the dealer. I just didn't have enough time or knowledge to move forward with the fix. I will update this post when I hear back from them (probably within a couple of days he said).
Thanks everyone for all the assistance (and knowledge).